scholarly journals Temporal Lobe Encephalocele Appearing as a Lytic Lesion of the Skull Base and Pterygoid Process

2003 ◽  
Vol 82 (4) ◽  
pp. 269-275 ◽  
Author(s):  
William E. Bolger ◽  
Christine Reger

Meningoencephalocele is an uncommon condition in which brain tissue, meninges, or both protrude through a defect in the anterior cranial fossa and into the ethmoid sinus or nasal cavity. Much less often, brain tissue, meninges, or both protrude through a defect in the middle cranial fossa and into the sphenoid sinus. We report an unusual case of a middle fossa encephalocele that appeared as a lytic lesion of the skull base. The patient was treated successfully via a unique endoscopic transpterygoid approach—that is, an endoscopic approach through the maxillary sinus and pterygopalatine fossa and into the pterygoid process.

2007 ◽  
Vol 61 (suppl_3) ◽  
pp. ONS-15-ONS-23 ◽  
Author(s):  
Yukinari Kakizawa ◽  
Hiroshi Abe ◽  
Yutaka Fukushima ◽  
Kazuhiro Hongo ◽  
Hatem El-Khouly ◽  
...  

Abstract Objective: The course of the lesser petrosal nerve is not well understood and may be confused with the course of the greater petrosal nerve during middle fossa surgery. The objective was to examine the course of the lesser petrosal nerve along the floor of the middle cranial fossa from the region of the geniculate ganglion to its outlet from the skull base. There are no studies focused on the course of this nerve in relationship to the floor of the middle cranial fossa. Methods: Twenty middle fossae from adult cadaveric specimens were examined using 3 to 40× magnification. Results: The lesser petrosal nerve was partially exposed on the floor of the middle fossa without drilling in 75% of the middle fossae and totally covered by thin bone in 25%. It crossed the floor anterior to the greater petrosal nerve and exited the middle fossa through the canaliculus innominatus in 14 cases, foramen spinosum in 3 cases, and the sphenopetrosal suture in 3 cases. The course of the lesser petrosal nerve has been shown in textbooks to be parallel to the greater petrosal nerve. However, the lesser and greater petrosal nerves diverged in the area medial to the geniculate ganglion in 90% of middle fossae with the angle of divergence averaging 11.6 degrees. The course of the lesser petrosal nerve was divided into three patterns based on the site of confluence of the three bundles of fibers forming the nerve. Conclusion: The relationships of the lesser petrosal nerve in the middle cranial fossa have been described. An understanding of these relationships will reduce the likelihood of it being confused with the greater petrosal nerve during surgical approaches to the middle fossa.


2019 ◽  
Author(s):  
Nauman Manzoor ◽  
Silky Chotai ◽  
Robert Yawn ◽  
Reid Thompson ◽  
Alejandro Rivas

2020 ◽  
pp. 1-10
Author(s):  
Kenichi Oyama ◽  
Kentaro Watanabe ◽  
Shunya Hanakita ◽  
Pierre-Olivier Champagne ◽  
Thibault Passeri ◽  
...  

OBJECTIVEThe anteromedial triangle (AMT) is the triangle formed by the ophthalmic (V1) and maxillary (V2) nerves. Opening of this bony space offers a limited access to the sphenoid sinus (SphS). This study aims to demonstrate the utility of the orbitopterygopalatine corridor (OPC), obtained by enlarging the AMT and transposing the contents of the pterygopalatine fossa (PPF) and V2, as an entrance to the SphS, maxillary sinus (MaxS), and nasal cavity.METHODSFive formalin-injected cadaveric specimens were used for this study (10 approaches). A classic pterional approach was performed. An OPC was created through the inferior orbital fissure, between the orbit and the PPF, by transposing the PPF inferiorly. The extent of the OPC was measured using neuronavigation and manual measurements. Two illustrative cases using the OPC to access skull base tumors are presented in the body of the article.RESULTSVia the OPC, the SphS, MaxS, ethmoid sinus (EthS), and nasal cavity could be accessed. The use of endoscopic assistance through the OPC achieved better visualization of the EthS, SphS, MaxS, clivus, and nasal cavity. A significant gain in the area of exposure could be achieved using the OPC compared to the AMT (22.4 mm2 vs 504.1 mm2).CONCLUSIONSOpening of the AMT and transposition of V2 and the contents of the PPF creates the OPC, a potentially useful deep keyhole to access the paranasal sinuses and clival region through a middle fossa approach. It is a valuable alternative approach to reach deep-seated skull base lesions infiltrating the cavernous sinus and middle cranial fossa and extending into the paranasal sinus.


2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S24-S24
Author(s):  
H Laharwani ◽  
T Woods ◽  
J Jackson ◽  
V Manucha ◽  
I Velasco

Abstract Introduction/Objective Cribriform adenocarcinoma of the minor salivary gland (CAMSG) is a recently described salivary gland neoplasm (SGN) that WHO includes under the polymorphous adenocarcinoma (PAC) subheading. CAMSG is reported to occur mostly in the base of the tongue and lingual tonsils. Methods We present a case of CAMSG of buccal mucosa in a 48-year old woman who presented with pain and swelling on the left side of the face that started after tooth extraction. Imaging revealed a large expansile mass (5.8 x 4.3 x 6.1 cm) originating in the left mandibular angle extending into masticator space, maxillary sinus, pterygopalatine fossa, sphenoid, middle cranial fossa, orbit and skull base. Ameloblastoma, primary intraosseous carcinoma, and squamous cell carcinoma were considered. Incisional biopsy revealed a tumor comprised of round to ovoid cells with clear to vesicular nuclei (ground-glass appearance) and occasional mitosis present in irregular solid, cribriform, and microcystic patterns in a hyalinized stroma with the presence of abundant mucin within lobules and stroma. Results Differential diagnosis of secretory carcinoma, hyalinizing clear cell carcinoma, and less likely PAC and mucoepidermoid carcinoma were considered, all inconsistent with the imaging findings. The tumor cells were positive for S100 and negative for CD117, ki67, p63, CD117, and TTF-1. Based on a prominent cribriform pattern, vesicular nuclei, and S-100 expression, a diagnosis of cribriform adenocarcinoma of minor salivary gland origin was rendered. The patient subsequently underwent left partial maxillectomy, left partial mandibulectomy, and resection of the skull base and left neck dissection and was staged as pT4bN0, with negative margins and vascular invasion. The patient underwent radiation therapy and at 6- month follow up was alive and healthy. Clinically and histologically CAMSG overlaps with tumors of both salivary and non-salivary gland origin. Conclusion Recognition of CAMSG as a distinct entity will help in accurate diagnosis and categorization in the WHO classification of SGNs.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Vipavadee Chaisuksunt ◽  
Lanaprai Kwathai ◽  
Kritsana Namonta ◽  
Thanaporn Rungruang ◽  
Wandee Apinhasmit ◽  
...  

All 377 dry skulls were examined for the occurrence and morphometry of the foramen of Vesalius (FV) both in the middle cranial fossa and at the extracranial view of the skull base. There were 25.9% and 10.9% of FV found at the extracranial view of the skull base and in the middle cranial fossa, respectively. Total patent FV were 16.1% (11.9% unilaterally and 4.2% bilaterally). Most FV were found in male and on the left side. Comparatively, FV at the extracranial view of the skull base had a larger maximum diameter. The distance between FV and the foramen ovale (FO) was as short as2.05±1.09 mm measured at the extracranial view of the skull base. In conclusion, although the existence of FV is inconstant, its occurrence could not be negligible. The proximity of FV to FO should remind neurosurgeons to be cautious when performing the surgical approach through FO.


2017 ◽  
Vol 13 (5) ◽  
pp. 614-621 ◽  
Author(s):  
Blake Harrison Priddy ◽  
Cristian Ferrareze Nunes ◽  
Andre Beer-Furlan ◽  
Ricardo Carrau ◽  
Iacopo Dallan ◽  
...  

Abstract BACKGROUND: In the last decade, endoscopic skull base surgery has significantly developed and generated a plethora of techniques and approaches for access to the cranial ventral floor. However, the exploration for the least-aggressive, maximally efficient approach continues. OBJECTIVE: To describe in detail an anatomical study, along with the technical nuances of a novel endoscopic approach to Meckel's Cave (MC) using a lateral transorbital (LTO) route. METHODS: Eighteen orbits of injected cadaveric specimens were operated on, using an endoscopic LTO approach to MC, middle cranial fossa, and paramedian skull base preserving the orbital rim. Surgical navigation and an after-the-fact infratemporal craniectomy were utilized to identify the limits of the approach. RESULTS: Following a transorbital approach opening a trapezoid window at the superolateral aspect (average 166.7 mm2), a middle fossa “peeling” and full visualization of MC was accomplished with no difficulties in all specimens. The entire approach was performed extradurally without the need to expose the temporal lobe. CONCLUSION: In a cadaveric model, the endoscopic LTO approach affords a direct route to access MC. Its main advantage is that it is minimally disruptive in nature, less brain retraction is required, and it reaches the middle fossa in an anterolateral perspective. It also requires no manipulation of the temporalis muscle, limited cosmetic incision, and rapid recovery. It seems a viable alternative to traditional approaches for lesions lateral to the cranial nerves at the cavernous sinus and MC, that is, schwannomas. Clinical utilization of this approach will challenge its efficacy and identify limitations.


2019 ◽  
Vol 81 (02) ◽  
pp. 165-171 ◽  
Author(s):  
Aida Nourbakhsh ◽  
Yang Tang ◽  
Brian S. DiPace ◽  
Daniel H. Coelho

Abstract Objective This study was aimed to better characterize the surgical anatomy of the floor of the middle cranial fossa using three dimensional Euclidean relationships between the arcuate eminence (AE), the superior semicircular canal (SSC), and the geniculate ganglion (GG). Study Design Submillimeter distances were recorded from computed tomography (CT) scans of 50 patients (100 sides). The AE, apex of the SSC, and the GG were identified and three dimensional distances measured. Setting The study was conducted at a tertiary academic teaching hospital. Main Outcome Measures In this study, Euclidean distance was obtained from AE to SSC by using a fixed anatomical landmark (GG) as the origin. Results On average, the AE is 2.1 ± 0.3 mm lateral, 2.5 ± 0.1 mm superior, and 2.1 ± 0.3 posterior to the SSC. Thirty percent (30/100) of patients had an AE that was less than 2 mm superior to SSC. The AE was medial to the SCC in 13% samples and anterior to the SSC in 18% samples. The results also show that there was no difference in mean distance between sides (1.08 mm; 95% confidence interval [CI] =  − 2.67–0.52; p-value = 0.29) or gender (0.56 mm; 95% CI =  − 1.34, 2.45; p-value = 0.86). Conclusions This study represents a comprehensive analysis of the relational anatomy of the floor of the middle fossa to date. In quantifying relationships between the AE, SSC, and GG, and by understanding the variability of these relationships in some planes, the middle fossa surgeon can feel more comfortable with this most challenging approach.


2011 ◽  
Vol 70 (suppl_1) ◽  
pp. ons157-ons162 ◽  
Author(s):  
Mika Komatsu ◽  
Fuminari Komatsu ◽  
Antonio Di Ieva ◽  
Tooru Inoue ◽  
Manfred Tschabitscher

Abstract BACKGROUND: Reconstruction of the skull base is essential to prevent postoperative leakage of cerebrospinal fluid (CSF). However, a reliable method of reconstructing the middle cranial fossa via a subtemporal keyhole is not available. OBJECTIVE: To determine whether less invasive reconstruction of the middle cranial fossa under endoscopic guidance with a pedicled deep temporal fascia approach via a subtemporal keyhole is feasible and useful. METHODS: The middle cranial fossa in 4 fresh cadaver heads was reconstructed with a 4-mm 0° rigid endoscope. RESULTS: A subtemporal skin incision (subtemporal incision) was followed by 2 small skin incisions (temporal line incisions) made on the superior temporal line. The endoscope was inserted through the temporal line incisions, and then the deep temporal fascia was separated from the superficial temporal fascia and temporal muscle under endoscopic view. A pedicled flap was harvested from the subtemporal incision and applied to the middle cranial fossa after subtemporal keyhole craniotomy. The pedicled deep temporal fascial flap was flexible, long, and large enough to overlay skull base defects. CONCLUSION: This purely endoscopic technique using a pedicled deep temporal fascial flap provided reliable reconstruction of the middle cranial fossa through a subtemporal keyhole. This technique would also be applicable in preventing CSF leakage or treating traumatic, acquired nontraumatic, or congenital encephalocele in the middle cranial fossa.


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